An integrated circuit package contain an integrated circuit (IC) in the form of a wafer or chip, and electrically conductive leads or pads extend from the chip. IC chips are generally mounted in carriers for test purposes and for protection of the leads.
As is well known in the art, IC carriers are often subjected to rigorous testing to ensure their stability and usefulness. Various IC carrier sockets have been developed for IC testing and burn-in procedures. Most of the development in IC carrier sockets has centered on providing zero insertion force (ZIF) characteristic in socket design as shown in U.S. Pat. Nos. 4,491,377; 4,623,208; and 4,715,823, and in my U.S. Pat. Nos. 5,114,358 granted May 19, 1992 and 5,205,756 granted Apr. 27, 1993.
In all the prior art devices identified above, flexible cantilevered contacts are spaced apart by some engagement of the contacts directly with some portion of a movable socket housing to allow introduction of the IC carrier into the socket with zero force exerted on the IC chip leads from the socket contacts. The IC carrier merely rests inside the socket until movement of the socket housing releases the contacts to engage the IC chip leads.
Inherent play in the movement of the base housing members creates functional and operational problems. Unbalanced tensioning of the contacts against the IC chip leads can result in a weak or failed electrical connection. The carrier itself may shift or even dislodge from the socket.